Shaping of sheet metal



T. M. yHARRISON.

SHAPING 0F SHEET METAL.

APPLICATION FILED SEPT.2|19I9.

1 ,$29,969. Patented Feb. 3, 1920.

2 SHEETS-SHEET T. M. HARRISON.

SHARING 0F SHEET METAL.

I APPLICATION FILED SEPT-2| l9l9. 1,329,969.-

4Patented Feb. 3,1920.

2 SHEETS-SHET 2.v

9 2 7 y 5l l" 3 /f f2. 9 /7 y ,l s?I 2f 'L 4 M- 40 I? 47240 f j# v n n i4f 156.

` J 416' 26 44 M j UNITED` sTATEs PATENT oEEIoE.

i 'rnRonoRE n. HARRISON, or IIAWTIIORN, MELBOURNE, VICTORIA, AUSTRALIAsHArING or SHEET METAL.

Patented Feb. 3, 1920.

Application filedv September 2, 1919. Serial No. 321,116.

To all whom it may concern.'

Be it known that I, THEoDoRE MARFIRET HARRISON, a subject of they Kingof Great Britain and Ireland residing in the cit of Hawthorn, a subur ofthe city of lllel- ,bourne, in the county of Bourke, State of Victoria,Commonwealth of Australia, and whose post-ollice address is 2 Hillstreet, in the said city of Hawthorn, have invented certain new anduseful Improvements in and Connected with the Shaping of Sheet Metal, ofwhich the following 1s a specification.

This invention relates to the bending and shaping of sheet metal byhydraulic power.

Sheetmetal has previously been yshaped in various-"ways, a method incommon practice being to place 'the metal to be shaped between apositive and a negative die and then press thetwo dies together. Theobjection to such a method has been the expense associated w-ith theconstruction of the dies and the powerful and costly machinery necessaryto operate them. A further objection has been the requirement ofdifferent dies according to the thickness of the material undertreatment.

The objectof the present invention is to provide a comparatively cheap,simple and effective apparatus in which sheet metal 'may be transformedto a desired shape in a speedy and economical manner. Aceord= ing to theinvention the sheet of metal to be shaped is gripped around its marginalportion between two relatively movable blocks and acquires the requiredshape by the aid of pressure water admitted to a flexible containerwhich forces the metal into a shaping recess or cavity in one of theblocks. The

sides or edges of the sheet are gripped in such a manner that althoughtightly held, the metal is' permitted to creep or slip inwardly to a'certain extent to take the shape of said recess when the hydraulicpressure is admitted. By this means the metal may beI converted to bothregular and irregulare forms without distortion or rupture. Any wrinklesforming Aat the marginal portion of the sheet are ironed or smoothed outas the metal is drawn inwardly. The invention is especially useful. inits application to the manufacture of panels, mudguards, or

other portions of motor vehicles, but may be applied for various otherpurposes.

Referring to the drawings which forml The iiexibl'e pressure watercontainer is in a collapsed state.

Fig. 3 is a plan of the lower block and the parts resting thereon. y y

Fig. 4 is a cross sectional view of a modification, the flexiblepressure water container being expanded and the sheet of metal forcedinto the shaping chamber by the hydraulic pressure.

Fig. 5 is a perspective view of the inventlon.

Fig. 6 shows a sheet of metal as it emerges from the machine after theshaping operation. The article being shaped is in this instance a cornerpanel for motor car bodies, but it will be obvious that the invention isequally applicable to the shaping of various other sheet metal articles.

Fig. 7 shows a finished corner panel after the out-turned border fiangeand the superfluous end portion seen in Fig. 6 have been removed.

`On reference to the seen that the numerals and loose pulleys on a 5 isa belt shifting device for moving the driving belt 10 onto either ofsaid pulleys. The shaft 4 carries a bevel pinion 6 which 'drawings itwin be 2 and 3 indicate fast vdrives a bevel wheel 7 on a worm shaft 8.A worm 9 on said worm shaft engages a wormV wheel 11 lixed on a mainshaft 12 which isas desired. p The lower end of each connect.

pulley shaft 4, whilev ing rod is pivoted to and supports a pin 20carried by an upper or shaping block 25` which moves along the guides14.

The underneath or grippin surface 21.

of the shaping block or of the epending lip Ithereof hereinafterdescribed, is, if necessary, longitudinally curved as in Fig. 1 toconform to the Shape that the border of the sheet metal is to acquire.Inside the border of the sha in block is formed a shaping recess or c amr 22., The area, hei ht an conformation of this recess or cham erdetermine the shape to be imparted to the sheet metal. Into said chamberthe metal is up wardly forced and shaped by hydraulic pressure ashereinafter described.

Preferably there is formed on the underneath surface of the upper blockand surrounding-l said chamber a depending lip 23. This lip conforms tothe marginal shape of said chamber and its inner edge or corner 24 whichforms the marginal edge or corner of the chamber is formed square asshown. This square corner of the shaping chamber in contradistinction toa rounded corner forms a material feature of the invention as it causesthe marginal portion of the sheet metal to be thoroughly ironed orsmoothed out as it is drawn inwardly by the hydraulic $0 preure. Beneaththe shaping block is a lower block 26. This block rests upon the base orfoundation 12 and may, if desired, be capable of being moved to .aslight degree either laterally or lonoitudinally in order that it may bereadily allned with the upper block. The upper surface 27 of the lowerblock may also be longitudinally curved to conform to the 'bordersurface 21 of the shaping block as shown.

Outside 'the lower block and situated in y any suitable position is avalve 29 controlling a water inlet pipe 31 which communi- Cates withawater passagewayv 32 leading to the'center of the upper surface of thelower block.-

A drain pipe 33 also communicates with said water passageway and isfitted with a pressure gage 34 and a discharge valve 36 for the purposeof draining the apparatus when the sheet metal has been shaped.

In combination with the foregoing a flexible pressure water container ofstout rubber, canvas or like elastic or flexible material is employed.This 4container is preferably in the form of a bag 37 which is closed onall l sides and is provided at its bottom with an orifice having an'pple 39 which is screwed or otherwise connected to the waterpassageway 32 of the lower blockas seen in Fig. 2. The marginal edges ofthe bag lie within the border of the chamber 22 1n the upper block.

The elastleor flexible bag preferablyl rests 65 on a protecting sheet 41 of rubber, fabric or y chamber 22.

driving belt is moved onto like material which lies on the upper surfaceof the lower block and has its edges turned up over the sides of the bagas at 42 to yprotect the latter from injury. A hole isformed through thecenter of this sheet to pass the nipple 39 of the bag.

Resting on the upper surface of the lower block is a rubber or likeflexible lpad or cushion 44. The inner edge 43 of this cushion conformsto the marginal shape of the chamber in the upper block and surround-sthe elastic bag above mentioned.

Resting upon said cushion is a metal ironing frame 46 upon which themetal sheet 45 to be treated is placed. The upper or gripping surface 40of this frame conforms to the shape or curvature of the surface 21.

he inner edge of said frame is provided with a 'square corner 47 andconforms precisely to the square marginal edge 24 of the chamber in theupper block beneath which edge it is disposed. The ironing frame 46 isheld in position by tongues 48 or other suitable means attached to thelower block.

Instead of the bag 37, the flexible pressure water container may be inthe form of `a rubber or other 'suitable flexible sheet 51 as shown inFig. 4. In this embodiment a jointing groove 52 is formed in the uppersurface of the lower block. This groove follows the marginal contour ofthe edge of the shaping` chamber 22 and above it is situated a combinedjointing and crowning v frame 53. The frame 53 which vis preferably madeof metal extends completely around the shaping chamber and upon it themetal sheet 45 to be treated is placed. When the upper block is loweredas in Fig. 4, it presses the marginal portion of the flexible sheet intothe jointing groove and thus forms a watertight joint-between said sheetand the lower block. If the bag 37 or sheet 51 are made of comparativel.inextensible vmaterial such as canvas, su cient slackness must be leftinside the gripped border to enable the container to fill out to theshape of the It will be seen that the cushion 44 in the one case and theflexible sheet 51 in the other form a resilient bed for the ironingframes 46 and 53 respectively, thereby allowing said frames to yieldslightly in a downward direction and allow the metal sheet 45 to creepinwardly between the ironing frame and Ithe vupper block when thehydraulic pressure is applied.

This invention operates as follows z-The the fast pulley by the belt`shiftingdevice which may, if desired, be arranged to automaticallyreturn the -belt to the loose pulley when the ecceny trics or crankshave been moved to their Y lower dead center position, as hereinafterdescribed. The worm ear rotates the main shaft and operates t eeccentrics to 'raise 130 of the upper block and the u of the metalironing frame.

the upper block sutiiciently to allow thesheet of metal under treatmentto be placed in position. Said sheet is placed on top of the ironingframe with its mariginal edges overlapping'the same to a su 'cientextent on all sides to provide a firm grip and allow of the inwardcreepage of the metal which occurs when the pressure water is admitted.The upper block is now lowered until the eccentrics or cranks havereached their lower dead center, the connecting rods thus holding theupper block down in operative osition without any possibility of upwarmovement when the hydraulic pressure is a plied. The marginal portion ofthe sheet o metal is now gripped between the lower-surface 21 er surface40 ressure water is now admitted to the flexible container causing thelatter to expand or lill out'and force the sheet of metal upwardlyT intothe shaping chamber until the sheet has assumed the precise shape ofsaid chamber, which will occur in a few moments after the admission ofthe pressure water. The pressure may now be cut off by closing the valve29 and the water released from the container by opening the' valve 36.The upper block is then raised and the shaped metal sheet removedvAlthough the border of the sheet is held i tightly between the upperblock and the ironing frame the hydraulic pressure causes the edges toadually creep or sli inwardly as the metal takes its new siia this beingpermitted by the yielding of the flexible cushion or sheet beneath theironing frame. The wrinkles or creases which form around the border ofthe metal sheety are thus elfectively ironed or smoothed out as themetal passes between .the cornersor edges 24 and 47 into the shapingchamber the shaped article emerging with perfectly .smooth sides and aborder flange out-turned squarely from the shaped portion of the sheetas in Fig. 6. This iange is afterward removed by suitable cuttersleaving a smooth and uncrinkled edge on the finished article as in Fig.`7.

By adj ustingthe length of the connecting rods 17 with the meansrovided, the grip on the sheet may be regu ated and differentthicknesses of metal accommodated.

- The invention provides a simple and effective means of `rapidlyimparting various shapes either regular or irregular to sheet metalwithout distortion, rupture or undue straining thereof.. The cornerpanel for motor car bodies with its varying contour from end to endillustrates a good example of the work performed bythe invention.`

Having now described my invention what I claim as new and desire tosecure by Letters Patent is 1. Apparatus for shaping and drawing Peasheet metal, com rising in combinationa pair of opposed b ocks, one ofwhich has its working face provided with a shaping cavity conforminginsize and shape to the article to be obtained, said cavity having amarginal gripping edge; a rigid, metal shaping f1 wme on vwhich the worksheet is adapted to rest, yieldingly' supported upon the other block andhaving a gripping edge for direct co-action with the first-namedmarginal gripping edge and which exactly conforms thereto in size andshape; means for producing a relative movement between said blocks in adirection to grip the work sheet between said co-acti edges; an eansible element between whic 'and the shaping lcavity the work sheet isinterposed; and means ,for applying iuidpressure immediately againstsaid expansible element to force it and the work sheet into said cavityand thereby shape the sheet against the walls thereof; the yieldingmounting of said shaping frame ena'bling it to yield slightly during theshaping operation so as to permit creeping of the sheet between thecoacting gripping edges- 2. Apparatus for shaping and drawing metal,comprising in combination a pair of opposed blocks, one of which has itsworking face provided with a shaping cavity conforming in size and shapeto the article to be obtained, said cavity having an abrupt marginalgripping edge; a rigid metal shaping frame on which the work sheet isadapted to rest, yieldingly supported upon ythe other block and havingan abrupt marginal gripping edge for direct co-actlon with thefirst-named gripping edge and which exactly conforms thereto in size andshape;'means for producing a relative movement between said blocks in adirection to grip the work sheet between saidv co-acting edges; an expansibie element between which and the shaping ca vity the work sheet isinterposed; and means for applying fluid pressure im` mediately a instsald expansi'ble element to force it an the work sheet into said cavityand 'thereby shape the sheet against the walls thereof; the yieldingmounting of said shaping frame enabling it to yield slightly during theshaping operation so as to per mit creeping of the sheet between thecoacting gripping edges; the square corners produced by the abruptformation of said edges acting to iron out and smooth the metal as thelatter passes between them into the shaping cavity.

3. Apparatus for shaping and drawing sheet metal, comprising incombination a pair of opposed blocks. one of which has its working faceprovided with a shaping cavity conforming i'i size and shape to thearticle to be obtained, said cavity having a marginal gripping edge; arigid, metal shaping frameI on which the work sheet is adapted elementto force it and the work sheet intol said cavityand thereby shape thesheet against the walls thereof; the yielding mounting of said shapingframe enabling it to yield slightly during the shaping operation so asto permit creeping of the sheet between the co-acting gripping edges'.

4. Apparatus for shaping and drawing sheet metal, comprising incombination a pair of opposed blocks, one of which has its working faceprovided with conforming in size and sha e to the article to beobtained, said cavity aving a mai-ginal gripping edge; arigid, metalshaping frame on which the work sheet is adapted to rest, yieldinglysupported upon the other block and having an open central portion, themarginal edge of which exactly conforms in size and shape to thefirst-named edge and is designed for direct co-action therewith; meansfor producing a relative movement between said blocks in a direction togrip the work sheet between said co-acting edges; an expansible elementbetween which and the shaping cavity the work sheet is interposed; andmeans for applying fluid pressure iinmediately against said expansibleelement to force it and the work sheet into said cavity and therebyshape the sheet against the walls thereof; the yielding mounting of saidshaping frame enabling it to yield slightly during the shaping operationso as to permit creeping of the sheet between the co-acting grippingedges.

5. Apparatus for shaping and drawing sheet metal, comprising incombination a pair of opposed blocks, one of which has its working faceprovided with a shaping cavity conforming in size and shape to thearticle to be obtained, said cavity havinga marginal gripping edge; theother block being formed with a fluid supply passage which opens throughits working face; a rigid metal shaping frame on which the work sheet isadapted to rest, yieldingly supported on the second-named block andhaving' a marginal gripping edge for direct co-action with thefirst-named edge and which exactly con-4 forms thereto in size andshape; means for producing relative movement between said blocks in adirection' to grip the work sheetbetween said co-acting edges; aflexible bag a shaping cavity mounted on the working face of thesecondnamed block and connected with said fluid supply passage, the worksheet being interposed between said bag and the shaping cavity; andmeans for supplying pressure fluid through said passage to said bag toexpand the latter and thereby force the work sheet into saidcavity andagainst the walls thereof; the yielding mounting of said shaping frameenabling it to yield slightly during the shaping operation so as topermit creeping of the sheet between the co-acting gripping edges.

6. Apparatus for shaping and drawing sheet metal, comprising incombination a pair of opposed blocks, one of which has its working faceprovided with a shaping cavity conforming in size and shape to thearticle to be obtained, said cavity having a marginal gripping. edge; arigid, metal shaping frame on which the work sheet is adapted to rest,having an open central portion the marginal edge of which exactlyconforms in size and shape to the first-named edge and is designed fordirect co-action therewith; a yielding cushion arranged upon the otherblock and upon which the shaping frame is immediately mounted; means forproducing a relathe yielding` mounting of said shaping frame enabling itto yield slightly during the shaping operation so as to permit creepingof the sheet between the co-acting gripping edges.

7. Apparatus for shaping and drawing sheet metal, comprising incombination a pair of opposed blocks, one of which has its working faceprovided with a shaping cavity conforming in size and shape to the arvticle to be obtained, said cavity having a marginal gripping edge; theother block being formed with a luid supply passage which opens throughits working face; a rigid metal shaping 4frame on which the work sheetis adapted to rest, having an open central portion the marginal edgeof'which exactly conforms in size and shape to the first-named edge andis designed for direct co-action therewith; a yielding cushion arrangedupon the second-named block and upon which the shaping frame isimmediately mounted, said cushion having an open central portion themarginal edge of which forms a continuation of that of the frameopening; means for producing relative movement between said blocks in adirection to grip the work sheet between said co-acting edges; anexpansible bag connected with the fluid supply passage and arranged uponthe second-named block within the confines of the openings in the frameand cushion, the work sheet being interposed between said 4 bag and theshaping cavity; and means for supplying pressure fluid through saidpassage to said bag to expand the latter and thereby force the worksheet into said cavity and against the walls thereof, the yielding THEO.M. HARRISON.

Witness JACK NANCE.

